Process and blank for the manufacture of middle rings of pipe couplings



Sept. 28, 19260 J. CLARK PROCESS AND BLANK FOR THE MANUFACTURE OF MIDDLERINGS OF PIPE COUPLINGS Filed July 19. 1924 Mount OJKM,

Patented Sept. 28, l926.

UNITED STATES PATENT OFFICE.

JAMES CLARK, 0F BRADFORD, PENNSYLVANIA, ASSIGNOR TO S. R. DRESSER MANU-FACTURING COMPANY, OF BRADFORD, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

PROCESS AND BLANK FOR THE MANUFACTURE OF MIDDLE RINGS OF PIPE COUPLINGS.

Application filed July 19, 1924. Serial No. 727,039.

My invention consists in the novel fea tures hereinafter described,reference being had to the accompanying drawing, which illustrates oneembodiment of the invention selected by me for purposes of illustration,and the said invention is fully disclosed in the following-descriptionand claims.

The object of my invention is to produce what is known as a wroughtmetal middle ring or coupling sleeve, of a rubber packed pipe couplingof the type illustrated in the United States Letters Patent granted toS. R. Dresser, No. 884,371, dated April 14, 1908, and which is used'inassociation with annular packing rings of rubber or other compressiblematerial, and clamping rings, the latter being connected by clampingbolts to compress the packing engaging portions of the middle ring, andbetween such portions and theexterior walls of the pipe sections to beconnected. These middle rings are provided centrally of their length andon their interior with an inwardly'projecting centering stop or riblocated substantially centrally of the length of the ring and the endportions of the ring are provided with packing engaging portions usuallyformed by outwardly flared end portions of the ring. The usual methodfor the commercial production of these rings consists in rolling a skelpof wrought metal substantially like that illustrated in United StatesLetters Patent to George H. White, No. 922,990, dated May 25th, 1909,consisting of a flat bar having a longitudinally extending centrallylocated rib on one face and having its lateral edges inclined so thatthey converge toward the beaded or ribbed face of the bar. Sections ofthis skelp or bar of the required length to form blanks for invidualrings are cut 03 from the main bar and after being heated to cherryheat, are rolled or bent into ring form and the ends of the blank areunited by welding. The ring so formed is then heated to cherry red,throughout, and subjected to the action of flaring devices which flarethe marginal portions of the ring outwardly, so as to provide packingengaging portions to receive the usual packing ring. These rings aremade in various sizes and it is necessary that they should bestandardized to within allowable limits of variations as to theirinterior diameter in order that they may fit over the meeting ends oftwo adjacent pipe sections, to be united, with the least possibleclearance consistent with due allowance for the slight irregularities inthe exterior surface of the pipe sections with which they are used. Itis customary, therefore, to subject these rings after the flaringoperation to. the simultaneous action of internal and external diesunder. hydraulic pressure, for the purpose of standardizing them as tosizeor internal diameter. It is found in practice that the rings varyconsiderably after the bending and flaring operations, on account of thevariation in the stretch lengthwise of the metal blank, and the finalstep of standardization, has the effect of stretching the rings if theyare-too small, or compressing them if they are too large, so as to bringthem to standard size. This process is entirely satisfactory for therings up to very considerable sizes in which the variation in thestretch of the blank is not too great to be corrected by thestandardizing dies,

and for which there is a sufliciently large demand to make itcommercially practicable to install the necessary standardizing dieswithout unduly increasing the cost of pro duction. In the manufacture ofrings of this kind in exceptionally large sizes, for example, three feetin diameter and up wards, the variations in the stretch would be sogreat that it is doubtful if they could be corrected by thestandardizing dies, and moreover, it would be prohibitive to make thenecessary die equipment to standardize these rings. It is found inpractice that the variations in the stretching of the blank due to therolling operation is from one half to one and a half inches in thediameter of the ring, while the allowable limit of va.

riation is of an inch in pipes, for example, of four feet in diameter.In the manufacture of these large size rings, there fore, it has beenthe practice to cutthe blank a little longer than necessary, bend theblank, into ring form, weld the ends together, in any desired manner,heat the entire ring to cherry red, and subject it to the flaringdevices to flare the end portions, ,with the result that a ring ofproper form is produced which is considerably larger than the standardsize. The ring is then carefully calipered around its internal peripheryand the exact length for-the finished ring is 'measured and marked. Theshort section of excess length is then cut out, by making two cutsthrough the ring wall, the ends are brought together, and again weldedover a mandrel of the proper size, which is of necessity collapsible, sothat it may be Withdrawn from the ring after the final weldingoperation. This results in the production of a ring of the requiredsize, but involves the cutting out of a section of the ring, and asecond welding operation, and a waste of material, all of which add tothe expense of production.

According to my present invention, I form a skelp or bar of apredetermined cross section, which will, when bent cold into ring form,produce the exact desired form of the finished ring. This bar or skelpcan be formed by rolling at the rolling mills, by means of suitablerollers, or it can be formed by rerolling the skelp of the typeillustrated in patent No. 922990 before referred to. A

section of this skelp of the exact length required to produce a ring ofthe desired size,

. is cut ofi from the special skelp bar, and is then bent cold into ringform so as to bring its meeting ends together. The ring is then welded,preferably by an electric welding apparatus, forming a bead weld upon acollapsible mandrel having its exterior diameter of the exact standardsize desired for the internal diameter of the ring, thereby completingthe ring by a single welding op eration, and dispensing with the flaringoperation, and also with the necessity for outtingout a section of thering and rewelding the ring which is required in the present methods ofproduction. is removed from the collapsible mandrel and is of exactlythe desired internal diameter within allowable limits of variation, andmay thus be made more cheaply than the rings produced by the oldermethods, and of any desired standard size. My invention also embracescertaindetails of construction and operation hereinafter more fully setforth and claimed in the claims forming part of this specification.

Referring to the drawing which forms part of this specification Fig. 1is a perspective view of a portion of a wrought metal skelp or bar fromwhich the individual ring blanks are cut, one of such blanks beingindicated in dotted lines;

Fig. 2 is an enlarged cross-section of the skelp or bar shown in Fig. 1;

Fig. 3 represents the ring blank bent into ring form and placed inengagement with a collapsible mandrel, illustrated conventionally, withits meeting ends abutted and unitedby welding; and

Fig. 4 is a view, partly in section, and partly in elevation, of arubber packed pipe The finished ring coupling in which one of thefinished rings is shown in operative relation with the packing rings,clamping rings and clamping bolts, and the connected pipe sections.

In carrying out my invention, I first preas indicated at 1, and isprovided on one face with a projecting longitudinal bead. At equaldistances on each side of the bead, 2, the skelp, which is ofsubstantially uniform thickness is given a slight obtuse angular bend ordeflection toward the beaded face of the skelp, as indicated at thedotted lines, 3, 3, and producing the angular portions, 4,

4, on opposite sides of the longitudinal center. The skelp is then givenan angular bend, as indicated at the dotted lines, 5, 5, a shortdistance outside of the adjacent bend, indicated by thedotted lines, 3,3, and from the bends, 5, 5, the skelp extends laterally in a horizontaldirection, that is to say, parallel to the plane of the central portion,but

slightly out of alignment therewith, forming the flat portions, 6, 6. Ashort distance back from the marginal edges of the skelp, the skelp orplate is given a longitudinal bend, indicated at 7, 7, backwardly, or ina direction away from the beaded face producing the angular portion, 8,8, having the beveled faces, 8 8, respectively. These beveled facesterminate in curved edge portions, 9, 9, which are connected to theopposite or unbeaded face of the skelp, by flat portions, 10, 10,parallel to the plane of the central portions, but disposed slightly outof alignment therewith, as clearly indicated in Fig. 2, in whichcontinuations of the planes of the opposite faces of the centralportions, 1, are indicated by the dotted lines,.

wy. It will be understood that the various bends indicated in Fig. 2,.extend longitudinally of the skelp or bar. The flat faces of thesections, 6, 6, indicated at 6, 6*, will form the interior walls of thepipe aperture at each end of the finished ring, as indicatedin Fig. 4,and it will be noted that the metal at each side of these pipeapertures, to wit, the portions, 4, 4 and 8, 8, extend in a directionaway from the pipe in the finished ring,so that the central portion ofthe skelp .or bar has its inner face out of alignment with the faces, 6,6 and this provides in the finished ring a certain amount of space orclearance, indicated at 11, in Fig. 4, which permits a slight angularmovement of the pipe ends within the coupling sleeve, or middle ring,while the faces, 8*, will provide a conical packing recess to receivethe packing rings of the couplings. As a result of this construction, tostandardize these rings it is only necessary to bring the inner faces.6?, 6 of the opposite pipe engaging portions of the rings to standardsize as slight variations in other portions of the ring will not affectthe operativeness thereof, while too great clearance at the oppositepipeiengaging portions would be very objectionable in that it vwouldpermit the packing to squeeze in too far, and if the diameter of thepipe engaging portions was too small, the pipe could not be inserted inthe ring. Bymaking the skelp in the form shown and described, therefore,

I reduce the portions which have to be standv ardized to a narrow bandrepresenting the inner surfaces, 6, of the portions, 6, 6.

After forming the skelp or bar in the form previously described asection of this bar is cut off, as indicated by the dotted line 2 in Fig1, to produce a blank of the length required to produce a ring of thedesired diameter. This can be readily calculated,

1 and this blank or skelp section is thenbent,

preferably by cold-bending operation without heating, to bring it intoring form with its ends abutting, and with the head, 2, on the inside,as shown in Fig. 3. The ring is 1 then placed upon a collapsible mandrel12, such as indicated in Fig. 3, having its exterior so shaped as toconform to the inner peripheral surface of the finished ring and toaccommodate the central rib or bead, 2, and the abutting ends of thering are welded, preferably by electric welding upon an electric weldingmachine, in any usual or desired manner, and while the ring is incontact with the mandrel, so that when the ring is formed, it will be ofthe desired standard size. Any desired form of collapsible mandrel canbe employed. In Fig. 3 I have shown, more or lessdiagrammatically, aform of mandrel comprising an annularportion formed in segments, asindicated in the drawing, and forming anlannulus' havinga conical innersurface, thesegments being held in proper position by means of a conicalplug, 12. This particular form of mandrel is known and need not be more.particularly described, and as'before stated, any other form ofcollapsible mandrel which can be withdrawn fromthe interior of the ringmay be employed. After the welding operation' the mandrel willbecollapsed and withdrawn, in any desired or usual manner.

As only a small portion of the ring on either side of the weld isheated, and as the ring is preferably bent cold, there is little or noscale formed, and there is no considerable variation in the stretch ofthe metal of different rings. It is found in practice that rings can bemade in this manner and brought to standard size within allowable 6limits of variation which will always exist under any method ofcommercial manufacture of such articles.

In Fig. 4 I have shown the completed ring in association with a pair ofpacking rings 13, clamping rings 14, connected by bolts 15, andapplied*to the meeting end portions of pipe sections,- indicated at16-16, the adj acent end portions of which are held separated by thebead. 2, now formed into an annular centering stop on the inner face ofthe ring. It will be observed that the inner faces 6 of the portions 6of the skelpprovide the pipe engaging portions at each end of the ring,as before stated, while the central portions 1 produce a cylindricalportion of slightly larger diameter, and thus enable the pipe ends to beaccommodated without requiring them to be in absolute axial alinement asthe clearance 11 permits slight angular positions ofthe pipe sectionswith respect to each other. The beveled portions 8 of the sections 8 ofthe skelp, in the finished ring produce the packing engaging recessesinto which conical portions of the packing rings. extend, and it will benoted that the exterior faces 10 at each end of the ring form annularfaces parallel to the axis of the ring over which the flange members 14;5 v

.formed without the center rib, and the rings may be formed withoutcentering stops if desired. Where the blank is rolled without the centerrib on one face, if it is desired to provide the rings made therefromwith a centering stop, this may be accomplished by welding one or moreprojections in line with the longitudinal center of the blank, upon theblank before bending it into ring form,

or thefinished ring may be provided with centering stops by weldingthereinone, two or more projections on the inner face of the ring.

It is also to beunderstood that the entire welding operation need not beperformed while the ring is on the mandrel, as I may and I usuallyprefer to weld the meeting edges of the ring for short spaces. separatedfrom each other, While the ring is so held. This is called tacking andis sufficient to hold the diameter or standard size of the ring correct.After such tacking the ring may be removed from the mandrel and passedon to other welders for finishing without the mandrel, by electricwelding or otherwise, and preferably without reheating the entire ring.

What I claim and desire to secure by Letters Patent is j 1. The hereindescribed process of forming standardized rings for pipe couplings,which consists in forming a blank of the required length when cold, toform a ring of the required standard size when its ends are ring formand bringing the ends together,

supporting the bent blank While cold on a standardized mandrel andbringing portions of the blank adjacent to the meeting edges themtogether in situ on the mandrel without materially heating the otherportions of the blank.

2. The herein described process of forming a standardized middle ring,for rubber packed pipe couplings having a. centering stop, and anoutwardly flared portion forming packing recesses, which consists inpreparing a blank of wrought metal of the required length when cold, toform the ring of required standard size when its ends are broughttogether, the said blank being provided with centrally locatedprojecting portions projecting from one face and disposed along a lineextending longitudinally of and centrally of said face, said blank beingalso provided at each of its longitudinal edges with flared portionsadapted to form the packing recesses when the blank is bent, bending theblank into ring form and bring- 'ing its ends together, supporting thebent blank while cold on a collapsible mandrel of standardized size,with its meeting ends inpos'ition to be Welded together andbringingp'ortions only of the. blank adjacent to said meeting edges towelding temperature and welding them together in situ on saidstandardized mandrel without materially heating the other portions ofthe blank.

3. The herein described process of forming a standardized middle ringfor rubber packed pipe couplings having a centering stop and flared endportions forming pack- 1 ing recesses, which consists ir forming a'blank of Wrought metal of a iength when cold to form a ring of therequired standard size when its ends are brought together, said blankbeing provided with a centrally located longitudinal rib projecting fromone face and longitudinally flanged edge portions adapted tofoi'm'packing recesses when the blank is bent, bending the blank whilecold into ring form and bringing the ends together, supporting the bentblank while cold on a collapsible mandrel with the end portions inposition to be welded together, andbringing portions only of the blankadjacent to its meeting edges to welding temperature and Weldinu themtogether in situ on said standardized mandrel without mabroughttogether, bending the blank into only to welding temperature and weldingterially heating the other portions of the blank, collapsing the mandreland removing it from the ring.

4. The herein described process of forming a standardized fniddle ringfor rubber packed pipe couplings, having a centering stop and flared endportions forming packing recesses, which consists in forming a blank ofwrought metal of a length when cold to form a ring of the requiredstandard size when its ends are brought together, said blank beingprovided with a centrally located longitudinal rib projecting from oneface and longitudinally flanged edge portions adaptedto form packingrecesses when the blank is bent, bending the blank while cold into ringform and bringing the ends together, supporting the bent blank whilecold on a collapsible mandrel with the end portions in position to bewelded together, bringing portions only of the blank adjacent to itsmeeting edges and at separated points longitudinally thereof to weldingtemperature and welding them together in situ on said standardizedmandrel without materially heating the ot her portions of the blank,collapsing the mandrel and removing it from the ring, and completing theweld ing of the meeting edges of the blank.

5. The herein described process of forming a standardized middle ringfor rubber packed pipe couplings, having a centering stop and flared endportions forming packing recesses, which consists in forming a blank ofwrought metal of a length when 100 cold to form a ring of the requiredstandard size when. its ends are brought together, said blank beingprovided with a centrally located longitudinal rib projecting from oneface and longitudinally flanged edge por- 1 tions adapted to formpacking recesses when the blank is bent, bending the blank while coldinto ring form and bringing the ends together, supporting the bent blankwhile cold on a collapsible mandrel with the end 110 portions inposition to be welded together, bringing portions only of the blankadjacent to its meeting edges and at separated points longitudinallythereof, to welding temperature and welding them together 115 withoutmaterially heating the other portionsof the blank. collapsing themandrel and removing it from the ring and completing the welding of thering by bringing only the portions thereof adjacent to the meeting 120edgesof the blank to welding temperature and welding them together insitu on said standardized mandrel, without at any time materiallyheating the other portions of the blank.

6. The herein described process of forming a standardized middle ringfor rubber packed pipe couplings, having a centering stop and endpacking recesses,- which consists in forming a blank of Wrought metal of130 a length, when cold, to form a ring of the required standard size,said blank having centrally located projecting portions disposed along aline extending centrally and longitudinally of one face thereof, andhaving on each side of said central longitudinal portions narrowlongitudinal portions having their inner faces parallel to the generalplane of the blank, but deflected out of alineoperation into ring formwith said central projecting portions and said narrow longitudinalportions on the inner side of the ring, sup porting the bent blankswhile cold on a collapsible standardized mandrel, having standardizingexterior faces to engage the inner faces of saidnarrow longitudinalportions of the blank, and bringing the meeting ends of the blank intowelding relation, bringing portions only of the blank adjacent to saidmeeting edges to welding temperature and welding them together in situon said standardized mandrel without materially heating the otherportions of the blank, to form a standardized pipe engaging portion ateach end of the ring between the central projections and the flangedportions thereof.

7. The herein described blank for a middle ring for pipe couplingsconsisting of a bar of wrought metal of the desired length to forin thering, said bar having flat longitudinal central portions, and beingprovided on each side of said central portion with longitudinallyextending narrow portions parallel with the central portions, butdeflected out of alinement therewith in a direction toward one face ofthe blank and connected with the central portions by angularly disposedportions, the longitudinal marginal portions of theblank being bent inthe op posite direction from said narrow longitudinally disposedportions, and forming a beveled portion at each longitudinal edge ofthebla 8. The herein described blank for a middle ring for pipecouplings consisting of a bar.

of wrought metal of the desired length to form the ring, said bar havingflat longitudinal central portions, and being provided on each side ofsaid central portion with longitudinally extending narrow portionsparal' lel with the central portions, but deflected out of alinementtherewith in a direction toward one face of the blank and connected withthe central portionsby angularly disposed portions, the longitudinalmarginal portions of the blank being bent in the opposite direction fromsaid narrow longitudinally disposed portions, and forming a beveledportion at each longitudinal edge of the blank, the opposite face of theblank being substantially parallel to the first-mentioned face except atthe marginal portions thereof, where it is provided with longitudinalfaces parallel with the flat central portions, but deflected out ofalignment therewith in a direction away from the first-mentioned face.

9. The herein described blank for amiddle ring for pipe couplingsconsisting of a bar of wrought metal of the desired length to form thering, said bar having flat longitudinal central portions, a centrallylocated longitudinal. rib projecting from one face thereof and beingprovided on each side of said central portion with longitudinallyextending narrow portions parallel with the central portions, butdeflected out of alinement therewith in a direction toward the ribbedface of the blank and connected with the central portions by angularlydisposed portions, the longitudinal marginal portions of the blank beingbent in the opposite direction from said narrow longitudinally disposedportions, and forming a beveled portion at each longitudinal edge of theblank, the face of the blank which is not provided with the rib beingsubstantially parallel to the ribbed face except at the marginal por--tions thereof, where it is provided with longitudinal faces parallelwith the flat central portions, but deflected out of alinement therewithin a direction away from the ribbed face.

In testimony whereof I afiix my signature.

JAMES CLARK.

